/Engine/Source/Editor/UnrealEd/Public/Kismet2/BlueprintEditorUtils.h
Will not change the category for functions defined via native classes.
static void SetBlueprintFunctionOrMacroCategory ( [UEdGraph](API\Runtime\Engine\EdGraph\UEdGraph) * Graph, const [FText](API\Runtime\Core\Internationalization\FText) & NewCategory, bool bDontRecompile )